Abstract: A method and apparatus is provided for 3D virtual try-on of apparel on an avatar. A method of fitting a garment on a person's body online may comprise receiving specifications of a garment, receiving body specifications of one or more fit models, receiving one or more grade rules, receiving one or more fabric specifications, and receiving specifications of a consumer's body. The value of one or more fabric constants may be determined according to the received one or more fabric specifications. One or more virtual garments in graded sizes may be created and stored in a database based on the received garment specifications and fabric constants. Moreover, one or more graded virtual fit models may be created and stored in a database based on the received specifications of the fit model. Each virtual garment may be draped on the related virtual fit model to create a fit-model drape. An avatar is received or created to represent a consumer's body shape.